Chop and onion and break up the broccoli. Fry onion gently in some butter until translucent. Add broccoli & stir fry for a minute or so. Add about 1 oint veg stock, reduce heat, season & keave to simmer for about 20 minutes.Leave to cool then blitz - check seasoning & reheat. Serve with a swirl of creme fraiche or cream